1. Field of the Invention
This invention relates to discharge devices of the types used as flash tubes and quench tubes in quenchable electronic strobe flash apparatus. More particularly, the invention relates to a discharge device which combines the operations of both a flash tube and a quench tube within a single compact structure.
2. Description of the Prior Art
As is well known in the electronic flash apparatus art, a quench tube is often employed to "quench" a flash tube after a predetermined amount of flash light has been produced. A flash tube and a quench tube have similar features. They each can comprise two spaced apart main current-carrying electrodes positioned at opposite ends of a hermetically sealed envelope which is filled with an inert ionizable rare gas, typically xenon, at a subatmospheric pressure. Both tubes must be capable of being triggered rapidly over the range of main electrode voltages used. Additionally, both tubes must be capable of handling relatively high currents.
On the other hand, to operate effectively the quench tube must meet certain criteria, which are different from those of a flash tube. Particularly, it must have a relatively low impedance compared to the flash tube. If the flash tube has a minimum impedance of typically 1 to 2 ohms, the quench tube should have an impedance of about 0.1 ohm.
In the prior art, the quench tube and flash tube are separate discharge devices. However, the use of two such separate discharge devices within a quenchable electronic strobe flash unit involves added problems with respect to cost, size, complexity, assembly, and the like.